The invention relates to a method for identifying the start of combustion in a cyclically operating internal combustion engine in which a fuel/air mixture is ignited by means of a corona discharge.
Ignition devices with which a fuel/air mixture is ignited by a corona discharge comprise an electrical resonant circuit, in which an ignition electrode that is electrically insulated with respect to combustion chamber walls constitutes a capacitor together with the combustion chamber walls. By exciting the resonant circuit, a corona discharge can be generated at the ignition electrode and then ignites the fuel/air mixture contained in the combustion chamber. Such a corona ignition device is described for example in WO 2010/011838. The content of the combustion chamber is the dielectric of the capacitor formed by the ignition electrode and the combustion chamber walls. Electrical variables of the resonant circuit of a corona ignition device are therefore particularly suitable for obtaining information regarding the combustion chamber and a fuel combustion process taking place therein.